Acoustic devices exist that fit into, at least partially, a user's ear canal, such as receiver-in-canal (RIC) hearing aids, personal listening devices, including in-ear headphones, and the like. For certain purposes, there is a benefit for such acoustic devices to have an open fitting or a closed fitting, such as back volumes, open/closed domes, vented shells, etc. As such, RIC hearing aids come in open or closed domes to provide for either open fittings or closed fittings, respectively. For an open fitting, acoustic signals are allowed to pass through the acoustic devices. Acoustic devices with an open fitting allow the natural passage of sound to the ear, which eliminates the occlusion effect. However, in an open fitting, the user may hear less of low frequencies. For a closed fitting, acoustic signals are not allowed (or at least limited) to pass through the devices. For acoustic devices with a closed fitting, loud background noise can be passively blocked by the closed fitting to better control the sound that reaches the ear. However, in a closed fitting, the occlusion effect generates unnatural sound.
Accordingly, a need exists for acoustic valves within acoustic devices that allow for the acoustic devices to switch between an open fitting and a closed fitting. Further, based on space constraints for such acoustic devices, a need exists for an active valve that does not impact the overall size of the acoustic devices.